Gear Train:
Meshing of two or more gear. It can transmit power from one shaft to another shaft.
Heat Treatment:
Operation involving heating and cooling of a metal in solid state for obtaining desirable condition without being changed chemical composition.Its object-increase hardness of metal.increase quality of metal ( heat, corrosion,wear resistance quality )improve machine ability.
Ferrous Metal:
1. Cast Iron – (2-6.67)%C, Si, Mn, P, S
2. Steel – (0-2)%C
3. Wrought Iron – 99.5% Fe
Non-Ferrous Metal:
1. Brass – (Cu+Zn)
2. Bronze –
(Sn+Cu) —— Tin Bronze
(Si+Cu) ——- Silicon Bronze
(Al+Cu) ——- Aluminium Bronze
Allowance:
It is the difference between basic dimension of mating parts. That means, minimum clearance between mating parts that can be allowed.
Tolerance:
It is the difference between upper limit of dimension. It is also the permissible variation above and below the basic size. That means maximum permissible variation in dimensions.
Stiffness:
It is the ability to resist deformation.
Toughness:
It is the property to resist fracture.
Fatigue:
When a material is subjected to repeated stress below yield point stress, such type of failure is fatigue failure.
Nuclear Fission:
It is a nuclear reaction by which one big nucleous divided into two or more nucleous.
Nuclear Fussion:
It is also a nuclear reaction by which one big nucleous will produced by adding two small nucleous.
Welding:
It is the process of joining two similar or dissimilar metal by fusion.
Arc Welding –
* need D.C current
* produced (6000-7000) Degree Centigrade Temperature
Gas Welding –
* Oxy – acetylene flame join metals
* Oxygen & acetylene gas works
* produced 3200 Degree Centigrade Temperature
Machine Tool:
It is the power driven tool. It cut & form all kinds of metal parts.
Example – 1. Lathe 2. Drill Press 3. Shaper 4. Planer 5. Grinding 6. Milling 7. Broaching 8. Boring
Cutting Tool:
Tool Materials for Cutting Tool:
1. High Carbon Steel
2. High Speed Steel (W+Cr+V)
3. Carbide (W Carbide+Ti Carbide+Co Carbide)
Indexing:
It is the method of dividing periphery of job into equal number of division. Actually, it is the process of dividing circular or other shape of work-piece into equal space, division or angle.
Jig:
It is one type of device which hold & locate work-piece and also guide & control cutting tool. It uses in drilling, reaming and tapping.
Fixture:
It is one type of device which hold and locate work-piece. It uses in milling, grinding, planning & turning.